Height in mid childhood and psychosocial competencies in late childhood: Evidence from four developing countries

We use longitudinal data from children growing up in four developing countries (Peru, India, Vietnam, Ethiopia) to study the relationship between height at the age of 7–8 and a set of psychosocial competencies measured at the age of 11–12 that are known to be correlated with earnings during adulthood: self-efficacy, self-esteem and aspirations. Results show that a one standard deviation increase in height-for-age tends to increase self-efficacy, self-esteem and aspirations by 10.4%, 6.4% and 5.1%, respectively. We argue that these findings are likely to be informing of an underlying relationship between undernutrition and the formation of non-cognitive skills.     

Household wealth and gender gap widening in height: Evidence from adolescents in Ethiopia,India, Peru,and Vietnam

This study investigates the relationship between household wealth and child height utilizing longitudinal data on 7150 children from Ethiopia, India, Peru, and Vietnam. The concept of conditional wealth is applied to separate the influence of wealth in early childhood. Conditional wealth is the change in wealth that was unpredicted at the age of 5 years. This study finds two dimensions of heterogeneity in the wealth-gradient of adolescent height: gender and stunting status at the age of 5 years. For all four countries in the study, the effect of conditional wealth on adolescent height is stronger for boys than for girls. The estimates for the pooled sample indicate that after the age of 5 years, the growth of children who were stunted at that age is significantly more responsive to conditional wealth than the growth of non-stunted children. The analysis results show that for boys in Ethiopia, a one-standard-deviation increase in preadolescence wealth is associated with an increase of 1 cm (standard error [SE]: 0.3) in height at the age of 15 years. For boys in the Indian state of Andhra Pradesh, Peru, and Vietnam, the corresponding figures are 1.1 cm (SE: 0.4), 1.8 cm (SE: 0.4), and 1.2 cm (SE: 0.4), respectively. The effect of preadolescence wealth on adolescent height is not statistically significant for girls, except in some regions. Overall, the results suggest that household wealth in preadolescence disproportionately benefits the male population in these countries when using height as a proxy for health.     

Differences in nutritional status between rural and urban Yucatec Maya children: The importance of early life conditions

Early-life conditions shape childhood growth and are affected by urbanization and the nutritional transition. To investigate how early-life conditions (across the “first” and “second” 1000 days) are associated with rural and urban children's nutritional status, we analyzed anthropometric data from Maya children in Yucatan, Mexico. We collected weight, height and triceps skinfold measures, then computed body mass and fat mass indices (BMI/FMI), in a cross-sectional sample of 6-year-olds (urban n = 72, rural n = 66). Demographic, socioeconomic and early-life variables (birthweight/mode, rural/urban residence, household crowding) were collected by maternal interview. We statistically analyzed rural-urban differences in demographic, socioeconomic, early-life, and anthropometric variables, then created linear mixed models to evaluate associations between early-life variables and child anthropometric outcomes. Two-way interactions were tested between early-life variables and child sex, and between early-life variables and rural-urban residence. Results showed that rural children were shorter-statured, with lower overweight/obesity and cesarean delivery rates, compared to urban children. Household crowding was a negative predictor of anthropometric outcomes; the strongest effect was in boys and in urban children. Birthweight positively predicted anthropometric outcomes, especially weight/BMI. Birth mode was positively (not statistically) associated with any anthropometric outcome. Cesarean delivery was more common in boys than in girls, and predicted increased height in urban boys. In conclusion, urbanization and household crowding were the most powerful predictors of Maya 6-year-old anthropometry. The negative effects of crowding may disproportionately affect Maya boys versus girls and urban versus rural children. Early-life conditions shape Maya children's nutritional status both in the “first” and “second” 1000 days.     

Accentuated lines in the enamel of primary incisors from skeletal remains: A contribution to the explanation of early childhood mortality in a medieval population from Poland

Physiological disruptions resulting from an impoverished environment during the first years of life are of key importance for the health and biological status of individuals and populations. Studies of growth processes in archaeological populations point to the fact that the main causes of childhood mortality in the past are to be sought among extrinsic factors. Based on this assumption, one would expect random mortality of children, with the deceased individuals representing the entire subadult population. The purpose of this study is to explore whether differences in early childhood survival are reflected in differences in deciduous tooth enamel, which can provide an insight into the development of an individual during prenatal and perinatal ontogeny. Deciduous incisors were taken from 83 individuals aged 2.0–6.5 years from a medieval inhumation cemetery dated AD 1300–1600. Prenatal and postnatal enamel formation time, neonatal line width, and the number of accentuated lines were measured using an optical microscope. The significantly wider neonatal line and the higher frequency of accentuated lines in the enamel of the incisors of children who died at the age of 2–3 years suggest the occurrence of stronger or more frequent stress events in this group. These results indicate that in skeletal populations mortality was not exclusively determined by random external factors. Individuals predisposed by an unfavorable course of prenatal and perinatal growth were more likely to die in early childhood. Am J Phys Anthropol 157:402–410, 2015. © 2015 Wiley Periodicals, Inc.     

Population level differences in adult body mass emerge in infancy and early childhood: Evidence from a global sample of low and lower‐income countries

Many studies have linked measures of adult body shape and mass in ancient and contemporary populations to ecogeographical variables such as temperature and latitude. These results tend to support Bergmann's rule, which posits that bodies will be relatively less slender for their height in colder climates and more slender in warmer climates. Less well explored is the ontogeny of these population‐level differences. Here we use data on infants and children from 46 low and lower income countries to test whether children's weight for height is associated with measures of temperature and latitude. We also test the hypothesis that children living in areas with greater pathogen prevalence will be lighter for their height because of life history trade‐offs between investment in immune function and growth. Finally, we test whether population specific adult body mass predicts infant and child body mass, and whether this is independent of ecogeographical variables. Our results show that maximum monthly temperature explains 17% of children's weight for height while adult population‐level body mass explains ～44% (Table 5 ). The measures of pathogen prevalence explain little of the variation in children's body shape (8%; P > 0.05). Our results suggest that population differences are consistent with Bergmann's rule but parental body shape explains more variance. Moreover, these population‐level differences arise early in development, suggesting that any possible environmental influences occur in utero and/or result from epigenetic or population genetic differences. Am J Phys Anthropol 154:232–238, 2014. © 2014 Wiley Periodicals, Inc.     

Employer-sponsored health insurance and labor market outcomes for men in same-sex couples: Evidence from the advent of pre-exposure prophylaxis

In the United States, the cost of providing employer-sponsored health insurance (ESI) varies for employers based on the medical expenditures of their employees, a practice known as “experience rating”. Experience rating increases the cost of employing workers who have greater medical expenditures, one example being men in same-sex couples. To study whether ESI affects labor market outcomes for men in same-sex couples, I use the 2012 advent of Pre-Exposure Prophylaxis (PrEP), a $24,000 per year drug that effectively prevents Human Immunodeficiency Virus (HIV) acquisition. Using American Community Survey data and a difference-in-difference empirical approach – comparing post-PrEP changes in earnings among men who have ESI – I find that annual earnings for men in same-sex couples decline by $2,650 (approximately 3.9%) relative to comparable men after PrEP becomes available. For those who are most likely to be taking Truvada (the brand name for PrEP), such as young men and white men, effects on earnings are considerably larger. I also observe a 3.7 percentage point (4.6%) decline in ESI prevalence and a 0.8 percentage point (10.7%) increase in part-time employment among men in same-sex couples. Event studies provide support for a causal interpretation for my findings. My estimates are also robust to placebo analyses, various specification permutations, and a range of sensitivity checks.